The 33-year-old model was asked by host Andy Cohen, 50, about the argument during a joint appearance with her 40-year-old singer husband in Los Angeles.
A viewer via Facebook wanted to know if the wedding fight rumor was true and what they argued about.
“I don’t even remember what it was about,” Legend said. “We try to think about this all the time,” Teigen added. “It was a major blowout to the point where … every time I see them, I feel like apologizing for it.”
While John seemed to think no one else knew about it, Chrissy corrected him, exclaiming, “Everyone knew!”
“I think I was really intimidated,” Teigen said. “I think it came from a lot of insecurity and, I just — I don’t know, a lot of fabulous, amazing people in one room. …” She identified another culprit: “And also drinking — so that doesn’t help.”
Watch the clip below.